#include <iostream>

using namespace std;

int ToNumAdd(const int n)
{
    int sum = 0;
    for(int i = 1; i <= n; i++)
    {
        sum += i;
    }
    return sum;
}

int main()
{
    int n = 0;
    cin >> n;
    int sum = ToNumAdd(n);
    cout << "The result of Add_n = " << sum << endl;
}
